<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    
</head>
<body>
    <script>
        // 高级api 不兼容 socket.io(一般使用它)
        let socket=new WebSocket('ws://localhost:3000');
        socket.onopen=function(){
            socket.send('我爱你你');
        }    
        socket.onmessage=function(e){
            console.log(e.data);
        }
    </script>
</body>
</html>